Azo dyestuffs



Patented July 25, 1944 Friedrich Felix, Basel, and Rudolf von Capeller, Riehen, Switzerland, assignors t the firm of Society of Chemical Industry in Basle, Basel,

Switzerland No Drawing. Original application July 8, 1938,

Serial No. 218,221. Divided and this application November 7, 1938, Serial No. 239,404. In Switzerland July 10, 1937 9 Claims. (01. 260-205) This applicationis a division of our application for patent Serial No.218,22l,.filed in U. S. A. on July 8, 1938. a i

It has been found that dyestuffs of the general formula wherein A is an aromatic nucleus of the benzene series which contains a nitro-group in para-position to the azo-group, B is an aromatic nucleus of the benzene or naphthalene series-and a: is

hydrogen or alkyl, and 1.! corresponds to the for- I wherein v is a divalent aliphatic, straight radical which may also contain substituents and z is a carbon bridge consisting of at least 2 and not more than 6 carbon atoms, are particularly valuable dyestuffs which in the form of their alkali salts are soluble in, water and may be used for dyeing various materials. These dyestuffs are red to dark powders and dye various materials orange, red, violet, blue and green tints. The expression a carbon bridge consisting of at least 2 and not more than 6 carbon atoms includes the radical of maleic acid, the CI-I= CH group, the radical of succinic acid, the -CH2+'CH2 group, the radical of phthalic acid, the CsI-I4 group; etc. i

Such dyestuffs are easily formed. by treating the compounds of the general formula wherein B is a substituent which in l-position to the N-group does not prevent the entry of a diazo-radical, r is hydrogen or alkyl, 11 is a divalent straight, aliphatic residue and z is the radical of an organic dicarboxylic acid, with the diam-compounds of compounds nitrated in-paraposition to the amino-group One may also start from the dyestufis of the general formula N0,-A-N=N' B n on z (wherein 'A, B, :c and uhave the significance given above) and treat thesame with dibasic dicarboxylic acids.

The azo-dyestufis obtainable by this invention contain, therefore an externally bound acid group. In consequence they form with neutraliz ing agents salts which dissolve in water, especial 1y salts of the alkalis or of ammonia. These dyestufis have, especially when besides the said acid residue of a polybasic acid, they contain no s ul fonic acid groups, a pronounced affinity for esters and-,ethers of cellulose and may, therefore, be used with advantage for dyeing and printing acetate artificialsilk. Ascompared with the insoluble dyestuffs they .have the advantage that they dissolve-easily'inwater and, therefore, re-

quire no dispersing agent for producing a fine distribution; As the residue of the organic acid v is only feebly acid in nature, it may be desirable to use in dyeing, small proportions of substances of alkaline reaction, for instance ammonia or an alkali salt of phosphoric acid or even an organic base, for instance pyridine, ethanolamine or the like. If the dyestufi is sparingly soluble or easily parts with the residue of the group which lends solubility, in dyeing, the dyestuff preparation or the dyebath may advantageously receive an addition of a dispersing or emulsifying agent, for instance soap or soap substitute.

Among the polybasic acids which are useful for making the new dyestuffs,- provided that they react with the dyestuffs or'suitable intermediate products, the following may be named: polybasic acids which may be used either as such orin the form of their anhydrides, halides, or esters of lo'w'molecular weight. Such acids are, for ex ample, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, pyridine dicarboxylic acids or the like, and also unsaturated acids like fumaric acid and maleic acids. Further phthalic acids, naphthalic acid and their sulfonic" acids come into question. Also sulfoacetic acid, sulfobenzoic acid, sulfosalicyclic acid may be used. 'These acids may be substituted in an aliphatic chain or'at the aromatic nucleus by any residue, for instance an alkyl group, a hydrox'yl group or an alkoxy group. The reaction with the aromatic hydroxyamine best occurs when this compound directly or in an organic solvent is heated with the acid, for which purpose, where it is possible, such a derivative of the acid is selected as is easily capable of esterifica ammonium or alkali metal salts. solutions dye wool, cotton, especially acetate artion, for instance an anhydride, a halide or an ester of an aliphatic alcohol of low molecular weight, for instance malonic acid ethyl ester. This reaction may be performed with the following bases: N- (methyloxyethyl) phenylamine, N (ethyloxyethyl) phenylamine, N-(methyloxyethyloxyethyl) -phenylamine, N (propyloxyethyl) phenylamine, N (isopropyloxyethyl) phenylamine, N-(butyloxyethyl) phenylamine, N- (isobutyloxyethyl) -phenylamine, N-amyloxyethyl) -phenylamine, N-(cetyloxyethyl) -phenylamine or the like. substituted as desired by a methyl group, an alkoxy group or the like, provided that the paraposition to the substituted amino-group still contains a. hydrogen atom which can be exchanged for the diazo-residue. There come also into question, suitable N-substitution products of 3- methyl-phenylamine, 5-methy1-2-methoxyphenylamine or the like, for instance N-(proploxyethyl) -3-methyl-phenylamine, N- (butyloxyethyl) -3-methylphenylamine. Also suitable N-substitution products of 3-acidylaminophenylamine,

The benzene nucleus may be by processes which are usual for producing esters from compounds containing hydroxyl groups and polybasic acids and the production may, therefore, be said to be an analogous process.

The following examples illustrate the invention the parts being by weight:

Example 1 able for the production of dyestuff by stirring it for instance 3-acetylamino-6-methoxy-1-(N-ethyloxyethyl) -phenylamine, N-(butyloxyethyl) -2- methoxy-5 aoetylaminophenylamine. Dyestuffs which dye equally well are produced by using such reaction products from N-(butyloxethy1(-2- methoxy 5 methyl)) phenylamine and N- (propyloxethyl(2 methoxy-5-methyl) -phenylamine.

These intermediate products are sparingly soluble in water but dissolve freely in dilute mineral acids and in water in the form of their alkali and alkaline earth salts.

When these compounds, which are'suitable for use as coupling components, are caused to react in neutral or feebly acid medium with diazo-compounds, dyestuffs are obtained which are soluble in water in the form of their alkali salts. As bases of which the diazo-compounds are used, there are suitable the aromatic amines commonly used containing a nitro-group in para-position, for instance 4-nitroaminobenzene, 4-nitro-2- chloraminobenzene, 4-nitro 2 methoxyaminobenzene, 4-nitromethylsulfonaminobenzene, 4- nitro 2 cyano-aminobenzene, 2:6-dichloro-4- nitroaminobenzene. Also 2:4-dinitroaminobenzene, 2 4-dinitro-6-cyanaminobenzene, 2 4-dinitrohalogenaminobenzene, 2:4 dinitro -'6 methylsulfonaminobenzene, 4-nitro-2-cyano-6- halogenaminobenzenes. One can also use, however, bases which contain sulfonic acid groups, for instance 4-riitroaminobenzene-2-sulfonic acid or the like.

As has already been stated, the finished a'zodyestufis which contain at least one hydroxyl group united to an aliphatic residue may be treated with polybasic acids of the kind'in question. This reaction may occur in a solvent or may also be conducted especially smoothly if the anhydride or halide of the organic acid selected is used.

' V The dyestuffs obtainable by the invention form salts with metals and in this form are soluble in general in water, particularly in the form of Such aqueous tificial silk, orangle, brown, red, blue and green tints. If the dyestuff contains a free amino-group it may be diazotized in substance and coupled with anycoupling component. This operation is advantageously conducted on the dyed fabric.

The intermediate products required are not described in the literature. They are obtainable in water and neutralizing with sodium carbonate or ammonia. This intermediate product has the formula COOH or the like, whereby products of similar properties are obtained.

Example 2 110 parts (10 per cent excess) of finely powdered maleic anhydride are stirred with 179 parts of N -(ethyloxethyl 3 methyl) phenylarnine'. The temperature rises to 50 C. and the mass is somewhat thick. While stirring, the temperature is raised to C. and kept thereat' for 2 hours. The mass is then cooled to 60-70 C. and dilute ammonia is gradually added to it in drops until it is feebly alkaline. This compound has the formula The procedure is the same in making the analogous product from succinic anhydride and also in making corresponding products from other aromatic bases which have as a substituent a. hydroxylated alkyl residue attached to the nitrogen. Thus there may be used for example malonic acid, preferably in the form of its dimethylester, further also adipinic acid, pimelic acid, suberic acid, quinolinic acid, and the like.

Example 3 sodium carbonate or'xammonia. The dry dyestufl' of the formula a 1 sulfonic acid with the. acid maleic acid ester of the N-hydroxyethyl-u-naphthylamine there is obtained a dyestuif which dyes wool violet tints'."

Example 4 Into a diazo-solution made from 216 parts of 4-nitro-2-m'ethylsulfonaminobenzene are introduced 263"parts of the-product of-Example,,,2 in the'form of 'an' aqueous solution of its ammonium salt. Th coupling is completed by prolonged stirring and a neutralizing agent, for instance sodium acetate, is preferably added. The .idyestuff is filtered and washed with some water. It is then stirred in water and brought to theneutral point by means of sodium carbonate or ammonia. When dry it is a dark powder soluble in water to a violetsolution and in aqueous solution dyeing acetate artificial silk, especially in a short liquor, fast violet tints. The dyestufi responds to the-formula sown:

By, using. the esters-.of Vdicarboxylic acids having artificial silk fast violet tints. The dyestuii' core responds to the formula s v. 1

noiQNeNg-l ion -onroeg-cnecn coon Cl H; 9 0 l A similar dyestufi is obtained when instead of the maleic acid ester of the above product the corresponding quantity of the maleic acid ester of Ne(hydroxyethyl-3 methyi-6- methoxy) phenylamine is used. This dyestufi corresponds to the formula.

There may also be used similar coupling components, for example of the formula cor- 40 a longer residue, for example dyestuffs of the 7 following constitution may be obtained G-n-om-grncm-o:

on. A i-cupcake 00H which are obtainable by treating the product 01 the reaction from monomethaniline and epichlorhydrine with succinic acid anhydride. The mobile 'y-chlorine atom may be exchanged, for example for a --CN group or also for the radical of thioglycollic acid, or for radicals containing nitrogen atoms. Thus thereniay be used for example coupling components of the formula Example s v 137 parts of 3-methyl-6-methoxyphenylamirl and parts of calcined sodium carbonate are Into the diazo-solution obtained from 171.5

parts of '4-nitro-2-chloraminobenzene are introduced 307 parts of the .monomaleic acid ester of N (ethyloxy-ethylfi 3-methyl-6-methoxy) e phenylamine in the form of an aqueous solutionof its ammonium salt. The coupling is completed by prolonged stirring and a neutralizing agent such as sodium acetate is preferably added. -The heated together at -80 C. Into the well stirred suspension of the sodium carbonate in the molten base there are dropped within 3-4 hours 228 parts .of para-toluene sulfonic acid butyl ester. Thewhole is stirred=further for 12 hours in the. course of which much carbon dioxideis evolved. On addition of water the monobutyl derivative separates in theiform of an oil, and is extracted by ether. By vacuum distillationit is purified. It boils at 140-143 C. under a pressure of 11 mms. V I

193 parts of N-buty1-( 3-methyl-6 methoxy) e phenylamine, parts of ,ethylene chlorhydrin and 30 parts of calcium oxide are heated together at 100 110" "C. for 24. hours Whilestirring" Swen.- The product is then mixed with water andithe whole extracted with ether. The final product boils at 160-168 C. under a pressure of 11 mins;

2.37 parts of N-butyloxethyl-(3-methyl-6- methoxy)-.phenylamine and ,108parts o maleic acid .anhydride' are stirred toge'therj at room temperature; v the. heat of the reaction, raised the temperature.to-abou't6,0 (1.,v at whihtfiihllglw. ture the viscous mass is maintained for ab tjl' hour by gentle heating. On cooling the esteriijed product solidifies. By stirring the masawith dilute ammonia in a small excess there is ob; tained a clear solution of the salt of the maleic acid ester.

335 parts-of this'acid maleic acid-esterof the formula i OCHa carom-011F011.

and dyes in aqueous solution acetate artificial silk fast red tints.

Example 7 335 parts of the maleic acid ester made as described in paragraph 3 of Example 6 from the base therein named in the form of a feebly ammoniacal solution are'pour'ed into a W611 stirred and ice-cooled solution of ,138.parts of diazctized 4-nitro-2-methylsulfonaminobenzene, By neu; tralizing the mineral acid with crystallized sodium acetate the coupling is brought to an end. There SOz-CH; CH:

The operation is the same when 4-nitro-6- chloro-2-methylsulfonaminobenzene or 2:4-dl- 'iiitro-G-chldro or bromoamino-benzene is used.

= 'Pr0ducts dyeing greentints are'obtained by using'the couplingcompone'nts-of the formuls,

'VNOI 0 is'also a valuable product. 7 I

Instead of the coupling components described in these examples, there may be used, for instance, an acid carboxylicoacid esterof 'N-butyloXyethyl -'(3' acet'ylamino -6- methoxy) phenylis Obtained a blue-violet dyestuff soluble in water;

in dry condition it is a dark powder which dissolves in water in the form of a salt and in this solution dyes acetate artificial silk deep blue-violet tints. The dyestufi corresponds to the formula the mixture is gradually added by drop while stirring. wellto a strongly-diluted and ice-cooled solution 'of 335 parts of the maleic acid ester made as described in paragraph 3 of Example 6. The solution should contain so much sodium acetate as is necessary for'neutralizing' the mineral'acid. The dyestuff'is filtered and neutralized in water with ammonia. iWhen dry it is a dark amine, similar dyestuffs being obtained. These coupling components may also be caused to react with the diazo-compound of 1-amino2:4-dinitro= fi-chlorobenzene whereby there is obtained a. bluedyeing dyestufi' of the formula n 00t V NOrQN=NNCHrCHr-O-fiCH=CH CO0H 4 NO: NH 0 I CHrCHrCHz-CH! CH3 I Redder dyestuffs are obtained by using acid carboxylic acid esters from N-(propylor N-(butyloxethyl) -phenylamine methylphenylamine.

Example 9 l 05 part of the ,dyestuff described in Examples is dissolved in 3000 parts of water. This dyeba th is then mixed with 40 parts of crystallized sodium sulfate and 100 parts of acetate artificial silk yarn are-handled therein for one hour at C After rinsing and drying, the artificial silk has a pure blue tint.

"Depending upon the'choice of dyestufi, acetate artificial silk can be dyed various tints. ."'The"-following table indicates other combinaor N- (butyloxethyl) -3- tions and colors produced thereby on acetate artificial silk.

stuffs are red todark powders which in the form of their alkali metal salts dissolve to orange to 4-nitro-2-metl1ylsulionaminobenzene 4-nitroaminobenzene 4 nitro-2-chloraminobenzene 4-nitro-2-methoxyaminobenzene 4-nitro-2-cyanaminobenzene 2:4-dinitrob-bromaminobenzene l 2:4-dinitro-6-bromaminobenzene 4-nitro-2-n1ethylsulfonaminobenzene.. 2:6-dichloro-4-nitroa1ninobenzene Monomaleic acid ester of ethyloxethyl-3-methyLG-methoryphenylamin Monomaleic acid ester of methyl-oxethyl-3-methyl-G-methoxyphenylamine R Monomaleic acid ester of methyl-oxethyl-3-methylwfi-methoxyphenylamine...

Morliomaleic acid ester of ethyloxythyl-3-methyl-6' o i.doIIIIIIIIIIIIIIIIIIIIIII"" Moniomaleic acid ester of cthyloxethyl o Diazo component Coupling component g i gg g gg 4-nitroan1inobenzene Monophthalic acid ester of methyloxethylphenylamine Scarlet 4-nitro-2-chloraminobenzene. Monophthalic acid ester of ethyloxethylphenylamine i. Red. 3-nitro-5-metl1oxyaminobenzene .do Yellow orange. 4-nitro-2-methoxyaminobenzene. do Red. 4-nitro-Z-methylsulfonaminobenzene do Red violet. 4-nitroaminobel1zene Monos Scarlet.

4-nitro-2-chloraminobenzene. i. do Bordeaux 4-nitro-2-metlioxyaminobenzene. do a. Red. 4-nitr0-2-n1ethylsulfon-aminobenzene. do Violet.

4-nitro-aminobenzenenihau Monomaleic acid e Scarlet.

. .4-nitro-2-chloraminobenzene. do Red.

'4 nitro-2-methoxyaminobenzene .do i Do. I 4-nitro-2-methylsulfonaminobeuzene.. Monomaleic acid ester of methyloxethyl Violet unethoxypbenyl amine What we claim is: p 1. The unsulfonated mono-azo-dyestufis of the general formula wherein A is an aromatic nucleus of the benzene series in which the nitro-group stands in paraposition to the -.-N=N--. group, B is an aror'natic nucleusselected from the group consisting of aromatic nuclei of the benzene and naphthalene series, a: is a member selected from the group consisting of hydrogen and alkyl and y group which 12 is linked to the :group and z is linked to the COOH-- group, wherein u is a divalent, aliphatic, straight radical consisting of at least 2 and not more than 3, ..carbon atoms, and z is a carbon bridge consisting of at least, 2 and not more than 6 carbon atoms, which dyestuffs are red to dark powders which in the form of their alkali metal salts dissolve to orange to red, to brown, to violet, to blue and,to green solutions.

2. The unsulfonated mono-azo-dyestuffs of the general formula wherein A is an aromatic nucleus of the benzene series in which the nitro-group stands in paraposition to the N=N- group, B is an aromatic nucleus selected from the group consisting of aromatic nuclei of the benzene and 9 naphthalene series, a: is a member selected from the group-consisting of hydrogen and alkyl and y a, i- ,7 i

- '-oH2-cHr-o-c-zgroup in which the CH2CH2 group is linked to the group and z is linked to the COOH group, wherein z is a carbon bridge consisting of at least 2 and not more than 6 carbon atoms, which dyered, to brown, to violet, to blue and to green solutions.

3. The unsulfonated mono-azo-dyestufis of the general formula group in which the CH2CH2- group is linked to the group and z is linked to the COOH group, wherein a is a carbon bridge consisting of at least 2 and not more than 6 carbon atoms, which dyestuffs are red to dark powders which in the form of their alkali metal salts dissolve to orange to red, to brown, to violet and to blue solutions.

4, The azo-dyestufi of the formula dissolving in water to a blue solution and dyeing acetate artificial silk similar tints.

5. The unsulfonated mono-azo-dyestuffs of the general formula NOzAN=NBlTT-y0 0 OH wherein A is an aromatic nucleus of the benzene series in which the nitro-group stands in paraposition to the N=N- group, B is an arc- 6 matic nucleus of the benzene series in which the N=N group and the group stand in para-position to each other, X is alkyl and is a group in which the CH2-CHz group is linked to the group and z is linked to the COOH group, wherein z is a carbon bridge consisting of at least 2 and not more than 6 carbon atoms.

6. A process for the manufacture of unsuifonated mono-azo dyestuffs of the general formula wherein A is an aromatic nucleus of the benzene series in which the nitro-group stands in paraposition to the N=N- group, Bis an aromatic nucleus of the benzene series in which the N=N group and the group stand in para-position to each other, X is 2 and not more than 6 carbon atoms, which comprises reacting a compound of the formula successively in any order with diazotized NO2ANH2, wherein the N02 group is in 1)- position to the NH2 group, and with HOOC-z--COOH 'A, B, X and 2 having the aforementioned significances.

7. A process for the manufacture of unsulfonated mono-azo dyestuffs which comprises reacting a compound of the formula wherein B is an aromatic nucleus of the benzene series capable of coupling at the 4-position to the group with a diazo compound, X is alkyl; and ii i I -onl-onro-o zgroup in which the CH2CH2 group is linked to the 7 N I X group and z is linked to the COOH group, 2 representing a carbon bridge consisting of at least two and not more than six carbon atoms, with a compound of the formula NOz-A-"-NH: wherein the N02 group is in p-position to; the NH2 group. I T

8. A process for the manufacture of unsuifonated mono-azo dyestufis which comprises re acting a compound of the formula Y NO;AN=NBNCHOH:OH I

wherein A is an aromatic nucleus of. the benzene series in which the nitro group stands in Ip-position to the N=N- group, Bis an aromatic nucleus of the benzene series in which the N=N- group and the group stand in p-position to each other, with a compound of the formula HOOC-a-COOH wherein z is a carbon bridge of at least two and not more than six carbon atoms until the corresponding half-ester is formed.

9. The unsulfonated mono-azo compounds, being the acids and the alkali metal and ammonium salts of the compounds which in the form 01' their acids are represented by the general tormula, i v 1 wherein A is an aromatic nucleus of the benzene series in which thelnitro-group stands in paraposition to the N=N group, B is an aromatic nucleus of I the benzene series in which the N=N group and the X group stand in para-position to each other, I is alkyl and 'y is a group in which the CHz-CI-Izgroup is linked to the Y r 1 V group and z is linked to the COOH wherein z is a carbon bridge consisting of at least 2 and not more than 6 carbon atoms.-

FRIEDRICH FELIX. RUDOLF VON CAPELLER. 

